Vacuum sealed remote control variable resistor



W. RYAN May 21, 1957 VACUUM SEALED REMOTE CONTROL VARIABLE RESISTOR Filed D90. 2, 1953 2 Sheets-Sheet l INVENTOR. -\/\/ILL,IAM Rm TTURNE Y May 21, 1957 w. RYAN 2,793,274

VACUUM SEALED REMOTE CONTROL VARIABLE RESISTOR Filed Dec. 2, 1953 2 Sheets-Sheet 2 ATTUHNEY United States Patent VACUUM SEALED REMOTE CONTROL VARIABLE RESISTOR William Ryan, New York, N. Y., assignor to Henry L. McCarthy, as Commissioner of Welfare of the City of New York and his successors Application December 2, 1353, Serial No. 395,753

12 Claims. (Cl. 20148) This invention relate-s to new and useful improvements in variable resistors or resistance units for electric circuits.

' More particularly, the present invention proposes the construction of an improved remote control variable resister which can be used to add and vary progressively and selectively resistance in an electrical circuit.

Another object of the present invention proposes forming the remote control variable resistor with a lineal resistance element and a fluid conductor having negligible or no resistance and providing means remotely controllable to move the fluid and the element relative to one another to cover the element to any depth desired with the fluid and thereby shorten it and change the resistance.

Still further, the present invention proposes constructing the remote control variable resistor with a resistor element chamber and a connected chamber to hold a fluid conductor such as mercury and providing a coolant and non-oxidizing gas in the resistor element chamber over the mercury to prevent overheating or a non-conductive oxide from forming on the fluid conductor.

As a further object, the present invention proposes arranging the remote control resi-stor with a hydraulically operated plate remotely controllable which will force the conductor fluid into contact with the resistor element and progressively inundate the element.

The present invention further proposes the arrangement of the remote control resistor so that the resistor element may be progressively and selectively moved into and out of the conductor fluid.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings, and to the appended claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

Fig. 1 is a vertical sectional view of the remote control variable resistor of the present invention.

Fig. 2 is a fragmentary view of part of the structure shown in Fig. l, with additional structure added toillustrate a modification of the present invention.

Fig. 3 is a View similar to Fig. 1 but illustrating a further modification of the prwen-t invention.

The new remote control variable resistor, in accordance with the first form of the invention, as shown in Fig. 1, has a casing 15. The upper part of casing is a hollow cylindrical tube 16 w-hich'is closed at the top by a cover 17 removably secured to the tube by bolts 18.

The lower end of tube 16 is fastened, as by bolts 19, to the upper end of a lower cylinder 20. This lower cylinder is also hollow with a closed upper end and .a lower end closed by a removable bottom cover 21'' held to cylinder by screws 22.

A positive terminal bolt plug 23 extends through .the-

2,793,274 Eatented May 21, 1957 bottom cover 21 and a negative terminal bolt 24 extends through the top cover 17. Positive and negative electrical lines 25 and 26 are connected to the terminals 23 and 24, respectively.

Within tube 1.6 is a vertically extending elongated chamber 27 and below this upper chamber is a second chamber 28 in the lower cylinder. A partition plate 29 is slidably mounted in and across the second chamber 28 dividing this chamber into two compartments, an upper compartment 3% and a lower compartment 31.

The partition plate 29 as shown consists of two electrically conductive members 32 and 33 with contact spheres or balls 34 between them. The casing parts, tube 16, cylinder 20 and covers 17 and 21 are made of non-conductive material such as rubber, fibreglas, nonconductive plastic and the like.

A resistance element 35 is disposed in the upper or resistance element chamber 27. The upper end of the resistance element 35 is connected to the terminal 24 and the lower end of the element extends near the lower end of the chamber.

Between the upper and lower chambers 27 and 28 extending through the closed upper end of the lower cylinder 20 and connecting the upper compartment 36 with the resistance element chamber 27 is a passageway 36. A valve 37 is provided in the passageway 36 to open and close the passageway.

Resistance element 35 preferably is made of high resistance material such as nichrome wire, coiled and spirally wound around a non-conductive core 38 to increase the length possible to put into the chamber 27 in the minimum of space. Core 38 has a spiral groove 39 around it in which the resistance coil 35 is contained with ample chamber space around the coil the full length of the groove. The lower end of the resistance element or coil 35 is secured to a conductor plate 46 which is fastened by screws 41 to the core 38 and spaced from and above the passageway 36.

A second conductor plate 42 is secured immediately below the passageway 36 in the upper compartment 30 of lower cylinder 20 by screws 43. A bellows type compression spring 44 of conductor material extends between the conductor plate 42 and the upper member 32 of the slidable partition plate 29. A similar spring 45 extends between the lower member 33 of partition plate 29 and the bottom cover 21. Spring 45 is electrically connected with terminal plug 23 by a conductor ring 46. Another compression spring 47 is provided in the upper compartment 30 between the plates 42 and 29. This plate may, but need not be, conductive.

Bottom cover 21 has an opening 4'7 through it and a conduit 48 connects this opening 47 with a hydraulic cylinder 49. A piston 50 in the hydraulic cylinder 49, a threaded piston rod 51 and a hand wheel 52 provide means to force hydraulic fluid 53 through the opening 47 in the bottom cover 21 into the lower compartment 31 of the chamber 28 of lower cylinder 20. Suitable shut-cit valves 54 and 55 and a pressure gauge 56 are provided in the conduit 48. 7 7

A fluid conductor 58, such as mercury, which has little or no resistance, is placed in the upper compartment 30 of the lower cylinder 20. Movement of the hand wheel 52 of the hydraulic cylinder and piston downwardly will exert hydraulic pressure through the hydraulic fluid 53 on the movable partition plate 29 and move the plate 29 toward the passageway 36. .This forcesthe conductor fluid 58 through the passageway. 36 into the resistance element chamber 27 and into contact with the lower end of the resistance element 35. Further movement of the hand wheel 52 will force the conductor fluid 53 up through the spiral groove 39 in the core and around the resistor element to any level desired. This will reduce the effective length of the resistance element and vary the resistance. The hand wheel and hydraulic cylinder may be remotely located from the rest of the device.

When the hydraulic pressure is released or lessened sufiiciently, the fluid conductor 58 will be returned by gravity to the upper compartment 30 out of contact with the resistance element 35.

To prevent over-heating of the portion of the resistance element not covered by the fluid conductor when the fluid conductor is in contact with the element, a coolant gas 59 is provided in the resistance element chamber 27. Preferably this gas is a non-oxidizing one which will not form an oxide on the fluid conductor and decrease or impair otherwise its conductivity. A relief line 69 is connected at the bottom of the chamber 27 and at the top of the chamber to permit the gas to escape and return as the fluid conductor displaces it. The relief line extends above the top of the chamber 27. V

The modification of the invention shown in Fig. 2 is characterized by the provision of a water jacket 61 around the resistor element housing tube 62. The remainder of the structure is the same as that shown in Fig. l and the parts are similarly numbered but primed. Water jacket 61 has an inlet opening 63 and an outlet opening 64 through which water 65 or other cooling fluid is passed.

The modification of the invention shown in Fig. 3 is characterized by the provision of a casing 66 having an upper chamber 67 and a lower chamber 68 with a passageway 69 between the chambers. A hydraulic piston 70 and cylinder 71 are mounted above the upper chamber 67. A piston rod 72 of non-conductive material is connected to the piston and extends into the upper chamber 68 in line with and normally held above the passageway 69.

A resistance element 73 is coiled and wound around the piston rod 72 outside the cylinder and extends down the rod to its lower end. A fluid conductor 74 fills the lower chamber 68.

Positive and negative terminals 75 and 76 are provided on the casing. The positive terminal 75 is connected to the upper end of the resistance element and the negative terminal 77 is connected with the fluid conductor 74 in the lower chamber 68.

Inlet and outlet conduits 78 and 79 to and from the hydraulic cylinder 71 connected to pumps (not shown) provide means to raise and lower the piston rod by hydraulic fluid (not shown) into and out of the chamber 68 filled with conductor fluid 74. In this manner the eflective length of the resistance element 73 may be changed and the resistance varied according to the extent the element is submerged.

While I have illustrated and described the preferred embodiments of my invention, it is to be understood that I do not limit myself to the precise constructions herein disclosed and the right is reserved to all changes and modifications coming within the scope of the invention as defined in the appended claims.

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent 1. A remote control variable resistor comprising a casing with a vertically extending chamber, a resistance element extending the length of the chamber, a second chamber with a passageway connecting the two chambars, a partition plate slidably mounted in and across the second chamber dividing it into two compartments, a hydraulic piston and cylinder connected with the compartment most remote from the first said chamber to move the plate toward the passageway and first said chamber, spaced positive and-negative terminals on the casing, one of said terminals being connected with the upper end of the resistance element and the other terminal being connected with the compartment of the second chamber adjacent to and connected with the first said chamber, and a fluid conductor in said compartment.

2. A remote control variable resistor comprising a casing with a vertically extending chamber, a resistance element extending lengthwise of the chamber, a second chamber, a partition plate slidably mounted across and in the second chamber dividing it into an upper and lower compartment, a passageway between the upper compartment and the first said chamber, a fluid conductor in the upper compartment, spaced positive and negative terminals on the casing, one of said terminals being connected with the upper end of the resistance element and the other terminal being connected with the fluid conductor in the upper compartment,- and a hydraulic piston and cylinder connected with the lower compartment to move the plate toward the passageway and the first said chamber and force the fluid conductor into contact with the lower end of the resistance element and progressively and selectively to inundate said element.

3. A remote control variable resistor comprising a casing with a vertically extending chamber, a resistance element extending lengthwise of the chamber, a second chamber, a partition plate slidably mounted across and in the second chamber dividing it into an upper and lower compartment, a passageway between the upper compartment and the first said chamber, a fluid conductor in the upper compartment, spaced positive and negative terminals on the casing, one of said terminals being connected with the upper end of the resistance element and the other terminal being connected with the fluid conductor in the upper compartment, and a hydraulic piston and cylinder connected with the lower compartment to move the plate toward the passageway and the first said chamber and force the fluid conductor into contact with the lower end of the resistance element and progressively and selectively to inundate said element, and means to cool the first said chamber housing the resistance element.

4. A remote control variable resistor comprising a casing with a vertically extending chamber, a resistance element extending lengthwise of the chamber, a second chamber, a partition plate slidably mounted across and in the second chamber dividing it into an upper and lower compartment, a passageway between the upper compartment and the first said chamber, a fluid conductor in the upper compartment, spaced positive and nega tive terminals on the casing, one of said terminals being connected with the upper end of the resistance element and the other terminal being connected with the fluid conductor in the upper compartment, and a hydraulic piston and cylinder connected with the lower compartment to move the plate toward the passageway and the first said chamber and force the fluid conductor into contact with the lower end of the resistance element and progressively and selectively to inundate said element, and means to cool the first said chamber housing the resistance element, said cooling means being a water jacket around the casing adjacent the resistance element housing chamber.

5. A remote control variable resistor comprising a casing with a vertically disposed elongated resistance element chamber, a resistance element extending lengthwise of the chamber, a second chamber below the resistance element chamber, a partition plate slidably mounted across and in the second chamber dividing it into upper and lower compartments, a passageway between the upper compartment and the resistance element chamber, a fiuid conductor in the upper compartment, spaced positive and negative terminals on the casing, one of said terminals being connected with the upper end of theresistance element and the other terminal being connected with the fluid' conductor in the upper compartment, a hydraulic piston and cylinder connected with the lower compartment to move the plate toward the passageway and the resistance element chamber, and means normally biasing the plate in the opposite direction.

6. A remote control variable resistor comprising a casing with a vertically disposed elongated resistance element chamber, a resistance element extending lengthwise of the chamber, a second chamber below the resistance element chamber, a partition plate slidably mounted across and in the second chamber dividing it into upper and lower compartments, a passageway between the upper compartment and the resistance element chamber, a fluid conductor in the upper compartment, spaced positive and negative terminals on the casing, one of said terminals being connected with the upper end of the resistance element and the other terminal being connected with the fluid conductor in the upper compartment, a hydraulic piston and cylinder connected with the lower compartment to move the plate toward the passageway and the resistance element chamber, and means normally biasing the plate in the opposite direction, said fluid conductor being mercury, a non-oxidizing gas in the resistance element chamber, and means for the gas to leave and return to the chamber when the mercury is forced into and permitted to withdraw from the resistance chamber by the plate.

7. A remote control variable resistor comprising a casing with 'a vertically disposed elongated resistance element chamber, a resistance element extending lengthwise of the chamber, a second chamber below the resistance element chamber, a partition plate slidably mounted across and in the second chamber dividing it into upper and lower compartments, a passageway between the upper compartment and the resistance element chamber, a fluid conductor in the upper compartment, spaced positive and negative terminals on the casing, one of said terminals being connected with the upper end of the resistance element and the other terminal being connected with the fluid conductor in the upper compartment, a hydraulic piston and cylinder connected with the lower compartment to move the plate toward the passageway and the resistance element chamber, and means normally biasing the plate in the opposite direction, said fluid conductor being mercury, a non-oxidizing gas in the resistance element chamber, and means for the gas to leave and return to the chamber when the mercury is forced into and permitted to withdraw from the resistance chamber by the plate, said gas escape and return means being a conduit having one end connected to the bottom of the resistance element chamber and the other end connected with the top of said chamber, the conduit extending above the chamber.

8. A remote control variable resistor comprising a casing with a vertically disposed elongated resistance element chamber, a resistance element extending lengthwise of the chamber, a second chamber below the resistance element chamber, a partition plate slidably mounted across and in the second chamber dividing it into upper and lower compartments, a passageway between the upper compartment and the resistance element chamber, a fluid conductor in the upper compartment, spaced positive and negative terminals on the casing, one of said terminals being connected with the upper end of the resistance element and the other terminal being connected with the fluid conductor in the upper compartment, a hydraulic piston and cylinder connected with the lower compartment to move the plate toward the passageway and the resistance element chamber, and means normally biasing the plate in the opposite direction, said resistance element being a coil spirally wound around a non-conductor core axially disposed in the re sistance element chamber.

9. A remote control variable resistor comprising a casing with a vertically disposed elongated resistance element chamber, a resistance element extending lengthwise of the chamber, a second chamber below the resistance element chamber, a partition plate slidably mounted across andin-the second chamber dividing it into upper and lower compartments, a passageway be tween the upper compartment and the resistance element chamber, a fluid conductor in the upper compartment, spaced positive and negative terminals on the casing, one of said terminals being connected with the upper end of the resistance element and the other terminal being connected with the fluid conductor in the upper compartment, a hydraulic piston and cylinder connected with the lower compartment to move the plate toward the passageway and the resistance element chamber, and means normally biasing the plate in the opposite direction, said fluid conductor being mercury, a non-oxidizing gas in the resistance element chamber, and means for the gas to leave and return to the chamber when the mercury is forced into and permitted to withdraw from the resistance chamber by the plate, said resistance element being a coil spirally wound around a non-conductor core axially disposed in the resistance element chamber.

l O. A remote control variable resistor comprising a casing with a vertically disposed elongated resistance element chamber, a resistance element extending lengthwise of the chamber, a second chamber below the resistance element chamber, a partition plate slidably mounted across and in the second chamber dividing it into upper and lower compartments, a passageway between the upper compartment and the resistance element chamber, a fluid conductor in the upper compartment, spaced positive and negative terminals on the casing, one of said terminals being connected with the upper end of the resistance element and the other terminal being connected with the fluid conductor in the upper compartment, a hydraulic piston and cylinder connected with the lower compartment to move the plate toward the passageway and the resistance element chamber, and means normally biasing the plate in the opposite direction, said fluid conductor being mercury, a non-oxidizing gas in the resistance element chamber, and means for the gas to leave and return to the chamber when the mercury is forced into and permitted to withdraw from the resistance chamber by the plate, said gas escape and return means being a conduit having one end connected to the bottom of the resistance element chamber and the other end conected with the top of said chamber, the conduit extending above the chamber, said resistance element being a coil spirally wound around a non-conductor core axially disposed in the resistance element chamber.

ll. A remote control variable resistor comprising a casing having an upper and lower chamber with a passageway between the chambers, a hydraulic piston and cylinder mounted above the upper chamber, a. piston rod on the piston of non-conductive material and extending into the upper chamber, a resistance element coiled and wound around the piston rod outside the cylinder and extending down the rod, 21 fluid conductor in the lower chamber, positive and negative terminals on the casing, one of said terminals being connected to the upper end of the resistance element and the other terminal being connected to the fluid conductor in the lower chamber, and means to raise and lower the piston rod and resistance element into the fluid conductor in the lower chamber through the passageway between the chambers.

12. A remote control variable resistor comprising a casing having an upper and lower chamber with a passageway between the chambers, a hydraulic piston and cylinder mounted above the upper chamber, a piston rod on the piston of non-conductive material and extending into the upper chamber, a resistance element coiled and wound around the piston rod outside the cylinder and extending down the rod, a fluid conductor in the lower chamber, positive and negative terminals on the casing. one of said terminals being connected to the upper end of the resistance element and the other terminal being References Cited in the file of this patent UNITED STATES PATENTS Ebeling Jan. 27, 19 20 Hai'gh't Oct. 4, 1927 Thompson Apr. 24, 1928 N fr 

